As a method of manufacturing a panel for an image display apparatus such as a color filter of a liquid crystal display, a method using a droplet ejection apparatus (ink jet drawing apparatus) is known (for example, see JP-A-59-75205). In this method, a plurality of pixels are formed on a substrate for manufacturing a panel on which a plurality of pixels (ejection regions) are formed by supplying a liquid material such as ink onto the plurality of pixels in the form of droplets using the droplet ejection apparatus. Such a droplet ejection apparatus for manufacturing a panel supplies the liquid material for forming pixels onto the plurality of pixels on the substrate by ejecting the liquid material in the form of droplets onto the substrate while mutually moving a stage for supporting the substrate with respect to a head unit on which a plurality of droplet ejection heads are provided.
A plurality of nozzles (nozzle openings) are formed in one droplet ejection head so as to be aligned, and the plurality of nozzles constitute a nozzle array. Since the length of the nozzle array is shorter than the size of the substrate, the plurality of droplet ejection heads are arranged on the head unit so that the nozzle arrays thereof connect each other when viewed from a scanning direction in order to make a width of a region on which droplets are ejected at one scanning operation of the head unit (a width to be drawn) longer.
However, since it is inevitable that some variations in the amount of ejection among the plurality of droplet ejection heads occur, for example, color of pixels onto which one droplet ejection head ejects droplets of the liquid material may become deep, and color of pixels onto which another droplet ejection head ejects droplets of the liquid material may become light. In such a case, there is a problem that color heterogeneity is generated in the panel.